Vibration motor primary flight control actuator

• US 20040238688A1
• Filed: 07/19/2004
• Published: 12/02/2004
• Est. Priority Date: 06/07/2001
• Status: Active Grant

• Current Assignee: Sagem SA (Safran SA)
• Original Assignee: Sagem SA (Safran SA)
• Inventors: Audren, Jean Thierry
• Granted Patent: US 7,165,746 B2
• Time in Patent Office: Days
• US Class Current: 244/75R
• CPC Class Codes: B64C 13/50 using electrical energy

Abstract

The invention provides an actuator for a control surface (7), in particular for a primary flight control of an aircraft, the actuator including a main actuator (3) in a main control line (1) for actuating the control surface (7), the actuator being characterized in that the actuator of the main control line (1) comprises a motor of the vibration motor type, and in that it further comprises, in a compensation, secondary control line (2), a compensation actuator (4) and spring-forming means (5) interposed between the compensation actuator (4) and the control surface (7), said compensation actuator (4) tensioning or compressing the spring-forming means so as to make them suitable for delivering a mean force to the control surface (7) so as to off-load from the main actuator (3) the mean force that it needs to deliver to the flight control (7).

Claims

1. An actuator for a control surface (7), in particular for a primary flight control of an aircraft, the actuator including a main actuator (3) in a main control line (1) for actuating the control surface (7), the actuator being characterized in that the actuator of the main control line (1) comprises a motor of the vibration motor type, and in that it further comprises, in a compensation, secondary control line (2), a compensation actuator (4) and spring-forming means (5) interposed between the compensation actuator (4) and the control surface (7), said compensation actuator (4) tensioning or compressing the spring-forming means so as to make them suitable for delivering a mean force to the control surface (7) so as to off-load from the main actuator (3) the mean force that it needs to deliver to the flight control (7).

2. An actuator according to claim 1, characterized in that the actuator (4) of the compensation secondary line (2) comprises a motor of the vibration motor type.

3. An actuator according to claim 1, characterized in that the compensation actuator (4) tensions or compresses the spring-forming means (5) when the main actuator is to supply a force having a non-zero mean value for a duration in excess of a threshold duration.

4. An actuator according to claim 3, characterized in that the threshold duration lies substantially in the range one second to twenty seconds.

5. An actuator according to claim 1, characterized in that the mechanical stiffness of the spring-forming means is selected in such a manner that the spring stroke needed for obtaining the maximum torque of the compensation actuator (4) is considerably greater than the stroke of the control surface (7).

6. An actuator according to any preceding claim, characterized in that the position of the compensation actuator (4) is blocked when it is exerting on the control surface (7) the mean force suitable for off-loading the main actuator of the main force it needs to deliver to the control surface (7), the main actuator (3) remaining in operational mode and then exerting on the control surface (7) only the forces required for fine maneuvering and stabilization of the aircraft.

7. An actuator according to claim 1, characterized in that the main control line includes electrical clutch-forming means (10) extending between the main actuator and the control surface, and enabling the control surface (7) to be decoupled from the main actuator (3) in the event of the main actuator malfunctioning.

8. An actuator according to claim 7, characterized in that the main line includes mechanical damper-forming means (11) extending in parallel with the electrical clutch-forming means.

9. An actuator according to claim 1, characterized in that the control signals for positioning the control surface (7) are determined by a flight control computer (12) and they are transmitted to the main and compensation actuators (3, 4) via electronic control means (13, 14).

10. An actuator according to claim 1, characterized in that the control signal for positioning the control surface (7) is transmitted to the main actuator (3), and a feedback loop (17, 19) extending between the main control line (1) and the secondary control line (2) enables the compensation actuator (4) to be controlled via lowpass filter-forming means (15) extending in the secondary line and electronic control means (14) interposed between the lowpass filter-forming means (15) and the compensation actuator (4).

11. An actuator according to claim 10, characterized in that the feedback loop (17, 19) extends between firstly a force sensor (16) interposed between the main actuator (3) and the control surface (7), and secondly the lowpass filter-forming means (15).

12. An actuator according to claim 10, characterized in that the feedback loop (17, 19) extends between firstly a circuit (18) for analyzing the control signals of the vibration motor, said control signals being representative of the torque delivered by the main actuator to the control surface (7), and secondly the lowpass filter-forming means (15), said analysis circuit extending from the electronic control means (13) of the main control line (1).

13. An actuator according to claim 10, characterized in that it includes means (22) for detecting large-amplitude maneuvers of the control surface (7) and then controlling means (21, 23) suitable for interrupting the feedback loop (17, 19) extending between the main control line (1) and the secondary control line (2) at the input to the transfer function (15) and suitable for interrupting the secondary control line (2) at the output from the transfer function (15).